This disclosure relates to semiconductor devices and methods of making same. More particularly, the disclosed subject matter relates to a method for making a device having a photodiode structure, and the resulting device.
Complementary Metal-Oxide-Semiconductor (CMOS) image sensors (CIS) are used in numerous applications including digital cameras, for example. For example, image sensors can be used for sensing exposed light projected toward a semiconductor substrate. CMOS image sensors generally include an active region having an array of light sensitive elements (pixels), and a periphery region. These products utilize an array of active pixels (i.e., image sensor elements or cells) including photodiodes and other elements (e.g., transistors) to convert images into digital data or electrical signals. Each of the photodiodes includes a p-type doped region and a n-type doped region to form a p-n junction for transforming photons into electrons when the photodiodes are exposed to light. The photodiodes are characterized by a dark current (DC) or a white pixel (WP) performance. There is a need for photodiodes having better DC and WP performance with minimal image lag.